This invention relates in general to the construction of control devices for respirators and in particular to a new and useful control for respirators including a controllable diaphragm valve.
A similar controllable diaphragm valve is known from U.S. Pat. No. 3,826,255. In general, a diaphragm valve in accordance with the invention is used in mechanical respiratory systems. Such a system comprises a valve casing enclosing a valve chamber. During an exhalation, the gases exhaled by a patient are directed through a gas inlet and a gas outlet of this chamber. During an inhalation, however, the diaphragm closes the gas inlet, thereby preventing the breathing gas being inhaled from flowing out. The closing is effected by the excess pressure produced in the control chamber above the diaphragm.
U.S. Pat. No. 3,826,255 discloses an exhaling valve comprising a cylindrical valve chamber, a gas inlet leading into the chamber to terminate in a valve seat, and a gas outlet. Extending opposite the valve seat is a diaphragm which can be sealingly applied against the valve seat. The diaphragm bounds a control chamber separate from the valve chamber. The diaphragm is held in place by a cover forming the other walls of the control chamber. Gas connections provided in the cover connect the control chamber to the controlling gas pressure source. The above exhaling valve is provided in German Pat. No. 29 47 363. This prior art valve comprises, centrally in the cover, a gas inlet connection for introducing gas into the control chamber and thus controlling the pressure to which the diaphragm is exposed.
To control the diaphragm in these prior art valves, a special control gas equipment is needed involving an additional risk of malfunction.